My understanding is that certain processes which are cut and dry and important are beginning to be handled by separate onchip circuits. For example, the MMU pag

My understanding is that certain processes which are cut and dry and important are beginning to be handled by separate onchip circuits. For example, the MMU page tables and TLB are no longer directly accessible from the chip; you have to message them like an abstract data structure, even inside the kernel. So in theory there is no exploit. Now Apple keeps moving more and more into what is essentially not software anymore. Parts of the renderer are abstracted. Perhaps there are validation routines for some kind of custom microcode that Apple is totally sure can not be compromised, the way we imagine a binary tree cannot be compromised as long as you use the approved methods of the class. For this they get security, and probably can design optimized purpose-built silicon that travels from process to process. I’m not saying exclaves are insecure, but how much of it is just a separate firmware based on undocumented procedures? If someone finds the secret key, can they overwrite the microcode, or is it really and truly permanent?